How to find the cause of OCMod not working?

Question

opencart

Opencart 2.2
When I enter the OCMod add-ons installation page, I see just a white screen. No errors are thrown.
what to do?)

Answer 1

The reason was the wrong version of LocalcopyOCMOD. Turned off - helped.

Answer 2

Did you turn on error display?

Answer 3

Hello! Can you tell me: I load the add-on using ocmod, it is displayed in the add-on manager, but there are no changes on the page on which the correction was planned. How to debug work?